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Model Output Discussion - 31/8/14 Onwards.


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Posted
  • Location: Derbyshire Peak District South Pennines Middleton & Smerrill Tops 305m (1001ft) asl.
  • Location: Derbyshire Peak District South Pennines Middleton & Smerrill Tops 305m (1001ft) asl.

With only an hour left of British Summer time, And ending with one the coolest August's in 20yrs, It's time for a new thread for the start of Autumn. Which looks to be starting off on a settled Summery note, With such mixed signals, The question is, Is for how long..

 

Please keep to Model Output based discussion, Respect others opinions and be polite  :)

 

Ok, Please continue.

 

Many Thanks, PM

Edited by Polar Maritime
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Posted
  • Location: Derbyshire Peak District South Pennines Middleton & Smerrill Tops 305m (1001ft) asl.
  • Location: Derbyshire Peak District South Pennines Middleton & Smerrill Tops 305m (1001ft) asl.

High Pressure seems to be holding on stronger and bang over the UK on tonight's GFS, Further into the run is showing a cool Northerly, With Heights pushing up towards Iceland and the Jet taking a dive to Spain..

 

gfsnh-0-192.png?18gfsnh-5-384.png?18gfsnh-0-372.png?18

Edited by Polar Maritime
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Posted
  • Location: Camborne
  • Location: Camborne

The anomalies are all more or less on the same page except the ECM which is still playing with a cut off low to the SW. It can probably safely be said the GFS and GEM giving a casual glance towards this scenario. Essentially we are looking at a ridge over the UK but the flow becoming more zonal in the further outlook.

 

Regarding the weekend the disagreement between the GFS and GEM continues apace. The former has HP off NW Scotland 1029mb bringing a dry NE,E flow over the UK with temps upper 60sF.

 

GEM on the other hand has a low in the 998mb in the SW approaches with fronts just touching Ireland on the Saturday. Similar temps. By Sunday the low is just off SW Ireland 991mb with front lying Ni/Cornwall/Devon.

 

 

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Posted
  • Location: Reigate Hill
  • Weather Preferences: Anything
  • Location: Reigate Hill

GFS continues with the HP outlook and on this morning's run, showing 16 days of mostly settled weather.

 

D16: post-14819-0-62347000-1409548035_thumb.p

 

There is background noise to this over riding signal, and with four runs a day it is expected that a hi-res run will pop up showing one of the other options, yesterday's 12z being a case in point. This morning it is the control that does something different:

 

post-14819-0-72039800-1409548667_thumb.p

 

A slowly sinking upper low/trough over the UK bringing showers and fronts. There is only a little support for this in the GEFS so unlikely based on current output. So whilst the ensembles support high pressure its best to run with this; though the GEFS also suggest that the op is unlikely (16 days of HP) and there are indications there may be a pattern change in 7-10 days, but little clarity and very uncertain from this suite, so waiting for further runs to compare.

 

GEM again this morning comes out with a slight variation on its recent theme, though has now moved the surface low from the UK, now more to the SW:

 

Saturday: post-14819-0-49980200-1409548254_thumb.p

 

Last night it's op had little support amongst its members with its mean: post-14819-0-86164400-1409548290_thumb.p

 

UKMO at D6 looking good for a dry weekend: post-14819-0-70757200-1409548448_thumb.g

 

NAVGEM into week 2: post-14819-0-01281700-1409548959_thumb.p

 

A nice week ahead with highs in the SE Wed-Friday of 23-25c, but warm most of England. By the weekend the high has moved and the wind direction changes (more NE/N), uppers also return to just above average (from 4-6c above this week) so closer to average  temps. A dry week after the front clears today:

 

Total week rainfall: post-14819-0-42249300-1409549825_thumb.g

Edited by i'm dreaming of...
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Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

Models show a benign early autumn pattern with gradually higher pressure this week and in any sunny breaks it will feel warm, actually in any decent sunny spells through the 2nd half of this week it will feel very warm with mid 20's celsius, probably most likely across the south of the uk, however, there will be often large amounts of cloud at times and where that occurs, temperatures will be closer to the high teens celsius range but at least the airmass is warm. The next few days show the southeast plagued by thicker cloud, mist and occasional drizzle and also a few sharp showers dotted around and only limited brightness but taking this week as a whole, it's a warm pleasant start to autumn.

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Posted
  • Location: Derbyshire Peak District South Pennines Middleton & Smerrill Tops 305m (1001ft) asl.
  • Location: Derbyshire Peak District South Pennines Middleton & Smerrill Tops 305m (1001ft) asl.

The Models continue to skip/jump about into week 2, With major differences showing from run to run.  So lot's of uncertainty, And given the change in Seasons the Models will also be struggling with background signals,  But interesting Model viewing never the less... As Im dreaming has stated, A sign of a pattern change could be on the cards.

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Posted
  • Location: Camborne
  • Location: Camborne

The ECM this morning also showing HP to the NW/N but some influence from a shallow low to the SW. This does tend to veer the upper circulation a tad but I'm not sure that explains the temps into the 23C range on Sunday.

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Edited by knocker
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Posted
  • Location: winscombe north somerset
  • Weather Preferences: action weather
  • Location: winscombe north somerset

Summer lives on past its use by date is the only observation i can gleen from todays output so far .I am going to enjoy this weeks pattern and hopefully it will last for a while ,but an ever increasing possibility of low pressure trying to gatecrash the party later in the far outlook [stay tuned ] cheers gang ,catch you all up later . :drinks:

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Posted
  • Location: chellaston, derby
  • Weather Preferences: The Actual Weather ..... not fantasy.
  • Location: chellaston, derby

The Models continue to skip/jump about into week 2, With major differences showing from run to run.  So lot's of uncertainty, And given the change in Seasons the Models will also be struggling with background signals,  But interesting Model viewing never the less... As Im dreaming has stated, A sign of a pattern change could be on the cards.

 

do they?.... the theme is still for high pressure to dominate, and the exact position and orientation are the only things thats changed, and thats not changed much.

 

previously several runs suggested that next weeks high might be positioned quite strongly to our northwest, with this weeks high drifting east and declining in strength...so much so that a northerly scourced draft would cross the uk. this morning the runs, including the anomaly charts have dropped that solution  but now suggest the next high builds and joins with this weeks centring itself to our near north.

 

its looking pretty clear that the first two weeks of september/autumn will be dominated by high pressure somewhere near the uk, probably on a northern latitude, putting most of the uk in a slack easterly draft.

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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

do they?.... the theme is still for high pressure to dominate, and the exact position and orientation are the only things thats changed, and thats not changed much.

 

previously several runs suggested that next weeks high might be positioned quite strongly to our northwest, with this weeks high drifting east and declining in strength...so much so that a northerly scourced draft would cross the uk. this morning the runs, including the anomaly charts have dropped that solution  but now suggest the next high builds and joins with this weeks centring itself to our near north.

 

its looking pretty clear that the first two weeks of september/autumn will be dominated by high pressure somewhere near the uk, probably on a northern latitude, putting most of the uk in a slack easterly draft.

 

 

To me the preference, at 500mb, still seems to suggest somewhere n of west of the UK for either an upper ridge or even possibly an actual high level centre?

Yes the ec-gfs have shifted slightly but unless noaa confirms that shift I would still suspect the upper centre to be n of west?

Perhaps I am wrong in that interpretation?

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

 

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

Edited by johnholmes
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Posted
  • Location: chellaston, derby
  • Weather Preferences: The Actual Weather ..... not fantasy.
  • Location: chellaston, derby

To me the preference, at 500mb, still seems to suggest somewhere n of west of the UK for either an upper ridge or even possibly an actual high level centre?

Yes the ec-gfs have shifted slightly but unless noaa confirms that shift I would still suspect the upper centre to be n of west?

Perhaps I am wrong in that interpretation?

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

 

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

 

oh im sure youre more accurate then me! lol, im a novice.

but the way i read them is that they have shifted from a strong high centred further from  our northwest, to closer, and possibly tracking eastward which ties in with the ops?...

 

of course this is fi, and i guess will be prone to subtle changes. as i see it what weather we get depends upon how high pressure remains to the east of next weeks high... northerly scourced (as per previous runs) as a result of lower pressure to the east of the high, or warmer easterly scourced if the pressure holds up east of the high centre.

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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

oh im sure youre more accurate then me! lol, im a novice.

but the way i read them is that they have shifted from a strong high centred further from  our northwest, to closer, and possibly tracking eastward which ties in with the ops?...

 

of course this is fi, and i guess will be prone to subtle changes. as i see it what weather we get depends upon how high pressure remains to the east of next weeks high... northerly scourced (as per previous runs) as a result of lower pressure to the east of the high, or warmer easterly scourced if the pressure holds up east of the high centre.

 

as with ANY model the anomalies MUST be used carefully and only when they are showing consecutive agreement from day to day and also consistency with one another and themselves.

So the idea of the +ve heights shifting slightly is acceptable but needs verification over a 2-3 day period to be sure they really mean it.

 

The 'high' you mention, is I suspect the anomaly heights you are referring to? The anomaly +/- need even more care than what the contours are predicted to do. Anything under about 60 be it + or - is only a slight anomaly and unless it is in the same/very similar area to where a trough/upper low or ridge/upper high is shown I tend to take not much notice of UNLESS they change to > than 60, again +/-.

Edited by johnholmes
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Posted
  • Location: Reigate Hill
  • Weather Preferences: Anything
  • Location: Reigate Hill

GFS has been calling this weekend as HP dominated for a while. ECM came on board a few runs ago and this evening the straggler, GEM finally follows it's mean and models the upper low more to the SW/W.

 

GEM: post-14819-0-00174200-1409589274_thumb.p  GFS:post-14819-0-49816100-1409589286_thumb.p

 

GFS still holds onto HP at D10: post-14819-0-21185400-1409589394_thumb.p

 

Possible changes re position of any high after D10, but that's well into FI. Though for the SW/S it is mainly settled till D16: 

 

post-14819-0-80502000-1409589622_thumb.p  A few op runs have been hinting at this.

 

As we suspected if GEM was wrong for the weekend, and it was, then other models and ensembles suggested HP in charge till around D10 at least. No surprise then that GEM 12z now agrees:

 

post-14819-0-55129000-1409589782_thumb.p

 

So x-model support (finally) for HP from today till D10 at least. Settled and warm this week. GEM warmer than GFS (average) for week 2 by 2-3c for the south.

Edited by i'm dreaming of...
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Posted
  • Location: Camborne
  • Location: Camborne

The ECM does have a slight variation on this theme. It's still keeping the upper low to the SW and over the weekend and into next week has the  high moving to the north east.

 

The upper circulation thus becomes more southerly orientated with warmer temps into the southern half of the UK. It's quite close to dragging even warmer air in. In theory that is.

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post-12275-0-74172400-1409597682_thumb.p

Edited by knocker
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Posted
  • Location: Evesham/ Tewkesbury
  • Weather Preferences: Enjoy the weather, you can't take it with you 😎
  • Location: Evesham/ Tewkesbury

My favourite model is gfs and it keeps the High pressure theme just about all its way! Ecm has a very different approach at T+168. My money this time is on the Ecm, and even though Ive no following to the Met office updates, they do keep banging on about unsettled conditions moving North with time....

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post-6830-0-19473300-1409601180_thumb.pn

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Posted
  • Location: Nuneaton,Warks. 128m asl
  • Weather Preferences: Snow then clear and frosty.
  • Location: Nuneaton,Warks. 128m asl

The 3 main runs now seem agreed on high pressure lasting through to the weekend.

Beyond that we seem to have less agreement with the ECM more bullish in moving the high away.

Looking at both ecm and gfs means at day 10 indicate pressure declining somewhat so next week may well see the Atlantic trough move east with a gradual breakdown in the settled conditions.

Tonights CPC anomaly charts indicate the movement around 10 deg.east of the long wave pattern in week 2 and is mentioned in their discussions

http://www.cpc.noaa.gov/products/predictions/814day/814day.03.gif

So a dry and quite warm week to come although it looks like there will be cloud around within this setup.

Next week suggests something less settled gradually developing from the southwest is my current thinking.

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Posted
  • Location: Camborne
  • Location: Camborne

Last nights anomalies have the ECM and GEM pushing the HP further east than NOAA and the GFS. The ECM and GFS also give more indication of an encroachment of the Atlantic from the SW.

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Edited by knocker
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Posted
  • Location: Camborne
  • Location: Camborne

The ECM this morning for next week has the low to the SW moving east in a duet with the HP. Tends to lead to a somewhat complex circulation over the UK, particularly in the south,  Temperatures going from quite reasonable to much cooler by Thursday.

 

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Posted
  • Location: Drayton, Portsmouth
  • Location: Drayton, Portsmouth

The ECM this morning for next week has the low to the SW moving east in a duet with the HP. Tends to lead to a somewhat complex circulation over the UK, particularly in the south,  Temperatures going from quite reasonable to much cooler by Thursday.

A bit of a turnaround from previous runs, when the low moved from west to east - does this suggest a portion of the jet running under the High? The ECM has really struggled with this low.

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Posted
  • Location: Camborne
  • Location: Camborne

A bit of a turnaround from previous runs, when the low moved from west to east - does this suggest a portion of the jet running under the High? The ECM has really struggled with this low.

 

Sorry not following that the low is still moving west-east. The jet splits way north and way south but significantly has a local jet in a somewhat strategic position.

post-12275-0-67855300-1409646208_thumb.p

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Posted
  • Location: chellaston, derby
  • Weather Preferences: The Actual Weather ..... not fantasy.
  • Location: chellaston, derby

The ECM this morning for next week has the low to the SW moving east in a duet with the HP. Tends to lead to a somewhat complex circulation over the UK, particularly in the south,  Temperatures going from quite reasonable to much cooler by Thursday.

 

i dont really understand that tbh, as the anomaly charts have been agreeing and consistent in suggesting an upper high north of the uk, possibly drifting east. im no expert but i wouldnt have thought the ecm's 00z surface synoptics matches with what the anomalies are showing. (by that i mean i wouldnt have thought the surface pressure charts would fit into the range of possibilities the anoms show)

 

maybe im wrong...

Edited by mushymanrob
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Posted
  • Location: Camborne
  • Location: Camborne

i dont really understand that tbh, as the anomaly charts have been agreeing and consistent in suggesting an upper high north of the uk, possibly drifting east. im no expert but i wouldnt have thought the ecm's 00z surface synoptics matches with what the anomalies are showing. (by that i mean i wouldnt have thought the surface pressure charts would fit into the range of possibilities the anoms show)

 

maybe im wrong...

 

Perhaps I worded that badly as I was talking about the low at 850 basically to get handle on the surface temps. There is no enclosed system on the surface charts that I've seen and the HP generally stretches from NW of the UK to eastern Europe.

post-12275-0-01507600-1409664213_thumb.p

Edited by knocker
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Posted
  • Location: chellaston, derby
  • Weather Preferences: The Actual Weather ..... not fantasy.
  • Location: chellaston, derby

Perhaps I worded that badly as I was talking about the low at 850 basically to get handle on the surface temps. There is no enclosed system on the surface charts that I've seen and the HP generally stretches from NW of the UK to eastern Europe.

 

oh it wasnt your post i didnt understand, it was the referance to what the ecm is showing, ive just got in and viewed the 00z which i didnt think is what the anomaly charts would produce, but i dont know, im no expert at reading them, so i could well be wrong and the ecm is in line with what the current anoms show.

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Posted
  • Location: Camborne
  • Location: Camborne

 

oh it wasnt your post i didnt understand, it was the referance to what the ecm is showing, ive just got in and viewed the 00z which i didnt think is what the anomaly charts would produce, but i dont know, im no expert at reading them, so i could well be wrong and the ecm is in line with what the current anoms show.

 

Perhaps it's better if one looks at the ops anomaly as it's the ops run rather than the ens 5 day spread. The little low traversing the channel. Just out of interest as we both know it certainly won't come to pass. I should have posted this initially.

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Edited by knocker
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Posted
  • Location: Derbyshire Peak District South Pennines Middleton & Smerrill Tops 305m (1001ft) asl.
  • Location: Derbyshire Peak District South Pennines Middleton & Smerrill Tops 305m (1001ft) asl.

I've just had to delete a post, Can we please only discuss Model Output in here.

Many Thanks, PM

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